ErrorFinder

Hello dear Tinker Board community, I have a question regarding the Tinker Board 2S when trying to install a different OS. I followed a tutorial and flashed my DietPi for the ASUS Tinker Board 2 with the Rockchip RK3399 onto a microSD card and inserted it into the Tinker Board. I also switched it to Maskrom mode and then powered it on, but it didn’t work. It just launched TinkerOS and never even attempted to boot from the microSD card or showed any error message. What am I missing?